Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Devices can be provided on the surface of the eye and/or within the eye to provide a variety of functions. In some examples, these functions can include functions to improve the ability of a person to view their environment (e.g., to provide an optical correction, to stimulate the retina directly) and/or to present additional visual information to the person (e.g., to present a heads up display or other indications to the person). Additionally or alternatively, these functions can include detecting a property of the body of a person (e.g., a blood glucose level, a concentration of an ion in the blood) via the eye, e.g., by accessing tears or other fluids that may be accessible on or within the eye and that have some relationship to the property of interest. Such functions can be provided by an external, eye-mountable device (e.g., a contact lens that is configured to detect a glucose level in tear fluid, to provide a static and/or controllable optical power to the eye, to provide light to the retina to indicate some information to a person) and/or by an intraocular device implanted within the eye (e.g., a retinal implant configured to stimulate the retina to restore vision, a device implanted within the lens capsule to provide a static and/or controllable optical power to the eye).